Method of and apparatus for producing cellular aggregate



T. E LLOYD Oct. 31, 1933.

METHOD OF AND APPARATUS FOR PRODUCING CELLULAR AGGREGATE Filed April 11,1931 4 Sheets-Sheet 1 INVENTOR. 4741 5.

A TTORNEYS.

Oct. 31, i933. T. E. LLOYD ,932,415

METHOD OF AND APPARATUS FOR PRODUCING CELLULAR AGGREGATE Filed April 11,1931 4 Sheets-Sheet 2 746W 5' ZZVENTOR. 7

BY M'v- I ATTORNEYS.

Oct. 31, 1933. E, LLOYD 1,932,415

METHOD OF AND APPARATUS FOR PRODUCING CELLULAR AGGREGATE Filed April 11,1931 4 Sheets-Sheet 5 7: 6, ZEVENTOR. BY 2 i zQq A TTORNEYS.

Oct. 31, 1933. T. E, LLOYD 1,932,415

METHOD OF AND APPARATUS FOR PRODUCING CELLULAR AGGREGATE Filed April 11,1931 4 Sheets-Sheet 4 M ZVE/VTOR.

ATTORNEYS.

Patented Oct. 31, 1933 UNITED STATES METHOD OF AND APPARATUS FOR PRO-DUGING CELLULAR AGGREGATE Thorne E. "Lloyd, Stanhope, J assignor toDwight & Lloyd Sintering Company, New York, N. Y., a corporation ofDelaware Application April 11, 1931. Serial No. 529,533

11 Claims.

This invention relates to a process and ap paratus for heat treatingmaterial and provides for successively treating layers of said materialto produce a light weight cellular aggregate. The invention isparticularly applicable 1 to the burning of material, such as clay,shales, argillities and similar rocks which preferably have a relativelyextended softening range, rather than a sharp melting point. The processis so carried out that the various layers are each completely heattreated before the next successive layer is applied thereto and theproduct comprises a cellular cake which is substantially homogeneous andin which the various'layers are joined together as an integral unit. Theheat treatment may be carried out by applying hot gases to the variouslayers or by drawing the gases through the layers as they aresuccessively passed through a heat treating ap .paratus.

The invention also consists in certain new and original features ofconstruction and combinatio'ns of parts hereinafter set forth andclaimed.

. Although the novel features which are believed to be characteristic ofthis invention will be particularly pointed out in the claims appendedhereto, the invention itself, as to its objects and advantages, andthemanner in which -it may be carried out, may be better understood byreferring to the following description taken in connection with theaccompanying drawings forming a part thereof, in which i Fig. 1 isa sideelevation of one form of apparatus for carrying'on the improved process;

Fig. 2' is a plan view of the roof of the apparatus showing thearrangement of the apertures;

Fig. 3 is a sectional view taken on the line .3-3 ofFig. 1;

Fig. iris a side elevation of a modified form of apparatus forpracticing the invention; and

Fig. dis a section taken on the line 5--5 of Fig. 4. I

. Like reference characters denote like parts in the several figures ofthe drawings.

In the following description and in the claims, various details will beidentified by specific names for convenience, but'they are intended tobe as generic in their application as the art will permit.

The present process for manufacturing light cellular aggregate consistsin heat treating a thin layer of raw material by passing therethroughgases heated to the proper temperature moved through chamber 25.

to-bring the particles into the state of incipient fusion whereupon theparticles are spun out into cellular form. A fresh layer of -material isthen applied which coolsthe first layer and causes it to retain itscellular form. The second layer is itself heated to the requiredtemperature and the process is repeated until a bed of desired thicknesshas been built up whereupon it is discharged from the heating apparatusand may be crushed and screened to'the desired size.

Referring to Figs. 13 an apparatus for carrying on this invention isshown which comprises a framework 10 carrying track 11 on which aplurality of movable pallets 12 are mounted. Said pallets are propelledalong track 11 by driving wheel 13 operated by a source of power '14through a gear train 15. Pallets 12 are prefervsaid pallets and isconnected by suction pipe 23 to a suitable source of suction (notshown).

Hinged doors 24 are provided for purposes of inspection or cleaning. v

Supported on frame 10 and mounted above pallets 12 is a heating chamber25 comprising roof 26, sides 27 and bottom members 28 which overhang thesides 20 of said pallets a sufiicient distance to shield said sides fromthe intense heat of said chamber. Said bottom members 28 are preferablyarrangedsufiiciently close to said pallets to form an effective seal andprevent leakage of gases. A further seal may be effected, if desired, byflexible members 30 which are secured to said side members and engagethe sides of said pallets.

A plurality of burners 31 communicate with ports 32 which extend throughsides 27 of said chamber. Said burners may be controlled by valves33'and are fed through a header 34 in any convenient manner. that anysuitable fuel, such as oil or gas, maybe employed and the ports arepreferably located a sufficient distance from the pallets to permitcomplete combustion before the gases come in contact with the bed ofmaterial. Valves 33 permit the regulation of the various burners so thatcontrol of the heat distribution within chamber 25 may be obtained. j

Roof 26 is provided with a plurality of transverse apertures 38 whichare arranged to distribute charge over the pallets 12 as they are Theapertures in' the various rows may be staggered, so that the It is to beunderstood charge to said roof.

through onto the pallets.

piles of material dropped through any one row will not fall directlyupon the piles dropped from the adjacent holes. A hopper 39 may bemounted in a convenient position to apply the A plurality of movablerabbles 40. mounted on an endlessbelt ll are adaptedjto engage saidcharge and distribute the same along said roof whereby it is applied tothe various apertures and caused to fall'there Said belt 41 may beoperated from power source 14 by any convenient drive such as belt 42.Side members .43 "are mounted on roof 26 to confine thelayer :ofmaterial to the area above the apertures .38.

It is to be understood that the size of theapertures 38 may be varied tocontrol the amount of material fed therethrough, for example, by the useof cast plates 60 having openings ofvarioussizes which may beselectively positioned in saidapertures.

Hoppers mis also mounted on frame lfl -inza position to dischargematerial to pallets 12prior: to-their passage through heating chamber25. v

In'the operation of the-above-described appa ;;ratus the interior oftheheating chamber is keptfilled with flame and-hot combustion products.by' the fuel burners; A thin layer of prepared charge isfed onto thepallets from hopper and is burnedby the flame which is drawn throughthe.

3o charge into wind box 22. The first row of aper era-blycrushedsufficiently fine to pass a charge in this form is droppedthroughtheaper- ,spreadinto, acomparatively uniform thin layer screen and ismoistened and thoroughly mixed to reduce the charge to smallpelletsa'preiterably gradingfrom A to down insize. .Asthee.

tures onto thelayer of -material already in. the pallet, it tends tospread. out, even though-- dropped in a series of small piles, thistendency being-increased by the generation of steam which- ,throws thepallets about violently .whenthey are first subjected to the highlyheatedgases. In

consequence, even-though the charge is dropped" on.-the layer-at a fewpoints spaced acrossv its width, within-a brief period'of time .-itwillhave oven. the entire. width ofthe pallet.-

The second layer is applied immediately after the-first. layer has.fused and expanded; and before the material thereof has. run togetherand lost itscellular condition. The second layer accordingly coolsthefirst layer and causes it to remainin a cellularcondition andialsoitis; quickly heated to'thefusion point and caused to firmlyadhere to thefirst layer so that the final- ,=product..comprises a homogeneous cakeof con siderablethickness and without cleavage planes or lines of.fracturebetween the individual layers.

A. modified form of apparatus for carrying on therinvention is shown inFigs. 4 and -5.- Inthis apparatus the frame 10, pallets 12,driving-mechanisn1..1l,,hopper 45 and heating chamber-25 are similar .inconstructionto that of Figs.'13 and have been 1 given similar reference.numerals. In this formofuapparatus,however, roof 26 is pro vided with aplurality of. transverse slots 50, each of which communicates with afeed hopper 51. Said feed hopper is provided with a discharge apparatus,such as rotating drum 52, by which a regulated quantity of material maybe removed from the hopper and applied through slots 50 to thepallets.Shields 53-maybe provided to prevent escape of gases frornslots 50 asmaterial is being applied thereto. The discharge apparatus maybe drivenby suitable gearing 54 which isconnected to the driving motor 14 as bybelt 55, and suitable gates 56 may be provided for controlling'theamountof discharge from hopper 51.

The operation of this form of device is similar to that above describedwith the exception that thphargeis--fed.from the various hoppers 51through slots 50. This form of apparatus may be preferable in certaininstances where an independent controloftherate of feed of the variouslayers is required.

A considerable variation in the product may be secured by suitablecontrol of temperature-and time of treatment given the'charge;With-high. temperatures and rapidtreatment aproduct is obtained havinglarger ceilabut being somewhat,

ess strong than that made withlcwer temperw tures. It will be understoodthat-the most suit able grade otaggregate Will :depend upon theparticular use to which it is put and the various: grades may beproduced bypropencontrol-of. the-operating conditions. For: example,an-ag gregate of maximum hardness will be desirable: for makingpartition blocks, which require com.- paratively lowstrength,whereasvawstrong and somewhat heavier aggregate may berdesirable :1

for use in wallsand floors which supporta-com siderable load. 7 r

The herein described process for makinglight a weight aggregate is rapidin operation, economi.-.-

cal requires but little labor-and acomparatively i:

small amount of fuel, makes an aggregate which ugg is exceptionallylight and extremely :uniformcinj character and may bereadilycontrclledfor pro ducing aggregate materials of various-degreesof. lightness and strength.

W'hile certain novel-features of the invention 1269 material by drawingexternally heated gaseslggr.

therethrough and substantially completing the treatment of each layerbefore thesucceeding layer is applied thereto. V

2. The continuous process 'of heat treating ma terials which comprisespassing a layer of' said' 'l35- material through a heating chamber,drawing externally heated gases through said materialf' therebyeffecting the desired heat treatment and applying additional layers ofsaid material at spaced points in said chamber while continuing 149? theheat treatment with externally'heated gases" so that each layer iscompletely heat treated before the next succeeding layer is appliedthereto.

3. The method of heat treating materials which said layer as itadvances-through:saidheatingrwm chamber whereby the successiveoperations are successively subjected to said preheated gases.

4. The method of heat treating materials which comprises passing saidmaterial in a thin layer through a heating chamber and drawing preheatedgases through said material to bring said layer to the state ofincipient fusion and applying a second layer of material to said firstlayer before said first layer has melted and run together, said secondlayer serving to cool said first layer and maintain the same in itscellular condition and itself being heated to the fusion point by saidgases and adhering to said first layer to form a uniform mass andrepeating the operation with the addition of successive layers to form amass of the desired thickness.

5. A heat treating apparatus comprising a heating chamber, a movablesupport, means for progressively passing said support through saidchamber and means for applying layers of material to said support atspaced points as it is passed through said chamber and means for passingexternally heated gases through said material whereby heat treatment ofsaid layers is progressively effected.

6. An apparatus for heat treatingmaterials comprising a heating.chamber, a plurality of pallets having perforate bottoms, means forapplying a layer of said material to said pallets and passing'saidpallets through said chamber, means for passing externally heated gasesdownwardly through said layer in said chamber and means forsuperimposing successive layers ofsaid material thereon as said materialadvances through said chamber.

7. An apparatus for heat treating materials comprising a heatingchamber, a plurality of pallets having perforate bottoms, means forapplying a layer of said material to said pallets and passing saidpallets through said chamber, means for passing externally heated gasesdownwardly through said layer in said chamber, means for superimposingsuccessive layers of said material thereon as said material advancesthrough said chamber, and means for regulating the thickness of each ofsaid layers whereby the heat treatment thereof may be controlled.

8. In an apparatus for heat treating materials, a heating chamber, meansfor passing a layer of material through said chamber, burners forintroducing hot gases to said chamber and causing complete combustion ofsaid gases out of contact with said material and uniformly applying theheated gases over the surface of said material, means for drawing saidhot gases through said material and means for superimposing successivelayers of material as said material-pas'ses through said chamber atspaced points.

9. In a heat treating apparatus, a heating chamber, means for applyingpreheated gases thereto, a movable support for passing a layer ofmaterial through said chamber, a plurality of feeding means spaced alongthe roof of said chamber and adapted to apply successive layers ofmaterial to said support, and means for draw ing said preheated gasesthrough material passing through the preheated chamber on said movablesupport.

10. A heat treating apparatus comprising a heating chamber, a pluralityof movable supports, means for passing said supports through saidchamber, means for applying a charge ofmaterial to said supports andcausing said charge to form a thin layer thereon, said heating chamberbeing provided with a roof having a plurality of transverse openingstherein, means for applying a charge of material to said roof andmeansfor spreading said material along said roof whereby it is caused tofall through said openings and to be applied to said movable supports ina plurality of successive thin layers.

11. A heat treating apparatus comprising a heating chamber, a pluralityof movable supports, means for passing said supports through saidchamber, means for applying a charge of material to said supports andcausing said charge to form a thin layer thereon, said heating chamberbeing provided with a roof having a plurality of transverse openingstherein, means for applying a charge of material to said roof, means forspreading said material along said roof whereby it is caused to fallthrough said openings and to be applied to said movable supports in aplurality of successive thin layers, said spreading means comprising aplurality of movable rabbles mounted on an endless belt and adapted toengage said charge and spread the same along said roof.

TI-IORNE E. LLOYD.

